UNAUDITED QUARTERLY RESULTS - Summary of Unaudited Quarterly Data (Details) - USD ($)	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Quarterly Financial Information Disclosure [Abstract]
Revenues	$ 70,035,000	$ 68,907,000	$ 69,642,000	$ 72,133,000	$ 74,117,000	$ 73,940,000	$ 74,315,000	$ 75,924,000	$ 280,718,000	$ 298,297,000	$ 318,293,000
Costs of sales and services, exclusive of depreciation and amortization	25,798,000	24,945,000	26,429,000	29,045,000	30,246,000	31,562,000	31,370,000	31,077,000	106,217,000	124,255,000	131,440,000
Costs of customer support	6,122,000	6,237,000	6,133,000	7,264,000	7,475,000	7,985,000	7,919,000	8,804,000	25,757,000	32,184,000	36,475,000
Goodwill impairment					1,936,000	78,169,000	0	0	0	80,105,000	0
Exit activities, restructuring and impairments	(148,000)	745,000	4,628,000	1,023,000	5,213,000	1,670,000	152,000	201,000	6,249,000	7,236,000	2,278,000
Net loss	$ (6,934,000)	$ (10,895,000)	$ (19,283,000)	$ (8,230,000)	$ (13,110,000)	$ (91,297,000)	$ (10,693,000)	$ (9,644,000)	$ (45,343,000)	$ (124,742,000)	$ (48,443,000)
Basic and diluted net loss per share (in dollars per share)	$ (0.35)	$ (0.55)	$ (0.97)	$ (0.51)	$ (1.01)	$ (7.01)	$ (0.82)	$ (0.75)	$ (2.39)	$ (9.54)	$ (3.73)